The present invention relates to a machine tool in which a feed member, such as a table or a head, is guided by a guide means and is fed by a drive means in a feeding direction relative to a fixed base member.
In a conventional machine tool, a table or a head is guided by a rail having a dovetail shape, for example. In such a guide means, a sliding contact between two facing members is inevitable.
Recently, higher and higher speeds have been required of the table or the head in the machine tool. For such a high speed feeding, several novel mechanisms have been suggested, with focus on link mechanisms because they have no sliding members such as rails or their counterparts. Some link mechanisms have been practically applied to high speed feeding in a machine tool. In such a high speed feeding, link mechanisms are intended to guide the feed member as well as to drive it.
In conventional link mechanisms, a plurality of axial members for feeding are driven via corresponding servo motors, so that the feed member moves in a predetermined linear path or curved path. Therefore, a complicated control program for driving the plurality of servomotors in synchronism is necessary. However, such a control program is troublesome to prepare and costly.